Chemical composition, antifungal, antibiofilm, and molecular docking studies of Syzygium dyerianum essential oil.

The current study describes the chemical composition, antifungal, antibiofilm, antibacterial and molecular docking studies of Syzygium dyerianum growing in Malaysia. The essential oil was obtained through hydrodistillation and characterized using gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). The antifungal and antibacterial activities were developed using the broth microdilution assay, whereas the effect on the microbial biofilms was determined using a semi-quantitative static biofilm assay. A total of 31 components were identified, which represent 99.5 % of the essential oil. The results revealed that the essential oil consisted mainly of ß-pinene (15.6 %), α-terpineol (13.3 %), α-pinene (11.1 %), caryophyllene oxide (8.8 %), limonene (8.1 %), borneol (6.0 %) and viridiflorol (5.1 %). The results of the microdilution method showed that essential oil exhibited activity against Candida albicans and Streptococcus mutans with minimal inhibitory concentration values of 125 and 250 µg/mL, respectively. Furthermore, essential oil decreased the biofilm of C. albicans and S. mutans by 20.11 ± 0.27 % and 32.10 ± 4.81 % when treated with 250 µg/mL. The best docking energy was observed with viridiflorol (-29.7 kJ/mol). This study highlights that essential oil can potentially be a natural antifungal, antibacterial, and antibiofilm agent that could be applied in the pharmaceutical and food industries.

A new R package to parse plant species occurrence records into unique collection events efficiently reduces data redundancy.

Biodiversity data aggregators, such as Global Biodiversity Information Facility (GBIF) suffer from inflation of the number of occurrence records when data from different databases are merged but not fully reconciled. The ParseGBIF workflow is designed to parse duplicate GBIF species occurrence records into unique collection events (gatherings) and to optimise the quality of the spatial data associated with them. ParseGBIF provides tools to verify and standardize species scientific names according to the World Checklist of Vascular Plants taxonomic backbone, and to parse duplicate records into unique 'collection events', in the process compiling the most informative spatial data, where more than one duplicate is available, and providing crude estimates of taxonomic and spatial data quality. When GBIF occurrence records for a medium-sized vascular plant family, the Myrtaceae, were processed by ParseGBIF, the average number of records useful for spatial analysis increased by 180%. ParseGBIF could therefore be valuable in the evaluation of species' occurrences at the national scale in support for national biodiversity plans, identification of plant areas important for biodiversity, sample bias estimation to inform future sampling efforts, and to forecast species range shifts in response to global climate change.

Evaluation of the Antiproliferative Potential of yellow Jaboticaba (Myrciaria glazioviana) extracts against Human Cervical Cancer (HeLa cells line) and the Analysis of their Chemical Composition by HPLC-HRESIMS.

Cervical cancer is a specific type of cancer that affects women around the world, with an incidence of 604 thousand new cases per year and 341 thousand deaths. There is a high demand for new effective antineoplastic drugs with few side effects. In this sense, recent research highlights the potential of compounds of natural origin in treating and preventing different types of cancer. Myrciaria glazioviana is a Brazilian native species belonging to the Myrtaceae family, which has previously described biological activities such as antimicrobial, anti-inflammatory, and antioxidant properties. This study aims to evaluate the anticancer activity of the dichloromethane extract (MGD) and ethyl acetate extract (MGA) of M. glazioviana leaves against human cervical cancer cell line (HeLa), as well as to identify their bioactive compounds. Using HPLC-HRESIMS technique, ten compounds were characterized in both samples: quinic acid, ellagic acid, Tri-O-methyl ellagic acid, two derivatives of Tetra-O-methyl flavellagic acid, quercetrin, Di-O-methyl ellagic acid, and three derivatives of pentamethyl coruleoellagic acid. Through MTT assays using HeLa cells and NIH/3T3 cells, it was observed that MGD and MGA were selective against tumor cells, with IC50 values of 24.31 and 12.62 µg/mL, respectively. The samples induced the tumor cell death by apoptosis, as evidenced by the activation of caspases 3/7, cell shrinkage, and pyknotic nuclei. Both samples were also able to inhibit the migration of HeLa cells after 24 hours of treatment, indicating a potential antimetastatic effect. Therefore, the present research highlights the antiproliferative and antimigratory potential of this species against HeLa cells.

Austropuccinia licaniae, first congeneric with the myrtle rust pathogen A. psidii.

In 1895 and 2001, rust fungi affecting Licania trees (Chrysobalanchaceae) in Brazil were described as Uredo licaniae by Hennings in the state of Goiás and as Phakopsora tomentosae by Ferreira et al. in the state of Amazonas, respectively. Recently, a Licania rust fungus collected close to the Amazonian type location sharing symptoms with the former two species was subjected to morphological examinations and molecular phylogenetic analyses using 28S nuc rDNA (ITS2-28S) and cytochrome c oxidase subunit III (CO3) gene sequences. Since the original type specimen of Ph. tomentosae is considered lost, we carefully reviewed the type description and questioned the identity of the telium, which justified the description of the fungus as a Phakopsora species. Furthermore, the additional revision of the type material described by Hennings revealed that Ph. tomentosae is a synonym of U. licaniae. Based on the morphological examinations, disease symptoms, and shared hosts, we concluded that the newly collected material is conspecific with U. licaniae. However, the phylogenetic analyses rejected allocation in Phakopsora and instead assigned the Licania rust fungus in a sister relationship with Austropuccinia psidii (Sphaerophragmiaceae), the causal agent of the globally invasive myrtle rust pathogen. We therefore favored a recombination of U. licaniae (syn. Ph. tomentosae) into Austropuccinia and proposed the new name Austropuccina licaniae for the second species now identified for this genus. The fungus shares conspicuous symptoms with A. psidii, causing often severe infections of growing leaves and shoots that lead to leaf necrosis, leaf shedding, and eventually to the dieback of entire shoots. In view of the very similar symptoms of its aggressively invasive sister species, we briefly discuss the current state of knowledge about A. licaniae and the potential risks, and the opportunity of its identification.

Undescribed Triterpenes from the Leaves of Syzygium myrsinifolium with Their α-Glucosidase and α-Amylase Inhibition Activity.

Two undescribed triterpenes, syzyfolium A (1) and syzyfolium B (2), together with twelve known compounds, terminolic acid (3), actinidic acid (4), piscidinol A (5), threo-dihydroxydehydrodiconiferyl alcohol (6), lariciresinol-4-O-ß-D-glucoside (7), icariol A2 (8), 14ß,15ß-dihydroxyklaineanone (9), garcimangosone D (10), (+)-catechin (11), myricetin-3-O-α-L-rhamnopyranoside (12), quercitrin (13), and 3, 4, 5-trimethoxyphenyl-(6'-O-galloyl)-O-ß-D-glucopyranoside (14) were isolated from the leaves of Syzygium myrsinifolium. Their chemical structures were determined by IR, HR-ESI-MS, 1D and 2D NMR spectra. Compounds 3 and 4 inhibited significantly α-glucosidase with IC50 values of 23.99 and 36.84, respectively, and compounds 1 and 2 inhibited significantly α-amylase with IC50 values of 35.48 and 43.65 µM, respectively.

Tautomeric cinnamoylphloroglucinol-monoterpene adducts from Cleistocalyx operculatus and their antiviral activities.

Guided by 1H NMR spectroscopic experiments using the characteristic enol proton signals as probes, three pairs of new tautomeric cinnamoylphloroglucinol-monoterpene adducts (1-3) were isolated from the buds of Cleistocalyx operculatus. Their structures with absolute configurations were established by spectroscopic analysis, modified Mosher's method, and quantum chemical electronic circular dichroism calculation. Compounds 1-3 represent a novel class of cinnamoylphloroglucinol-monoterpene adducts featuring an unusual C-4-C-1' linkage between 2,2,4-trimethyl-cinnamyl-ß-triketone and modified linear monoterpenoid motifs. Notably, compounds 1-3 exhibited significant in vitro antiviral activity against respiratory syncytial virus (RSV).

NMR and multivariate methods: Identification of chemical markers in extracts of pedra-ume-caá and their antiglycation, antioxidant, and enzymatic inhibition activities.

INTRODUCTION: In Brazil, the plant group popularly known as "pedra-ume-caá" is used in folk medicine for the treatment of diabetes, and its raw material is commonly sold. OBJECTIVE: The aim of the study was to apply a method for chemical identification of extracts of dry pedra-ume-caá leaves using HPLC-high-resolution mass spectrometry (HRMS) and NMR and develop a multivariate model with NMR data to authenticate commercial samples. In addition, to evaluate the biological activities of the extracts. MATERIALS AND METHODS: Dry extracts of Myrcia multiflora, Myrcia amazonica, Myrcia guianensis, Myrcia sylvatica, Eugenia punicifolia leaves, and 15 commercial samples (sold in Manaus and Belém, Brazil) were prepared by infusion. All the extracts were analysed using HPLC-high-resolution mass spectrometry (HRMS), NMR, principal component analysis (PCA), and hierarchical cluster analysis (HCA). The antidiabetic effect of extracts was evaluated according to enzymatic inhibition. Their content of total phenols, cell viability, and antioxidant and antiglycation activities were also determined. RESULTS: HPLC-HRMS and NMR analysis of these extracts permitted the identification of 17 compounds. 1H NMR data combined with multivariate analyses allowed us to conclude that catechin, myricitrin, quercitrin, and gallic and quinic acids are the main chemical markers of pedra-ume-caá species. These markers were identified in 15 commercial samples of pedra-ume-caá. Additionally, only the extracts of M. multiflora and E. punicifolia inhibited α-glucosidase. All the extracts inhibited the formation of advanced glycation end products (AGEs) and showed free-radical-scavenging activity. These extracts did not present cytotoxicity. CONCLUSION: This study revealed the chemical markers of matrices, and it was possible to differentiate the materials marketed as pedra-ume-caá. Moreover, this study corroborates the potential of these species for treating diabetes.

Insecticidal activity of essential oil from leaves of Eugenia stipitata McVaugh against Aedes aegypti.

Aedes aegypti, a mosquito, is responsible for the spread of many diseases, including dengue, zika, and chikungunya. However, due to this mosquito's developed resistance to conventional pesticides, effectively controlling it has proven to be challenging. This study aimed to evaluate the insecticidal potential of the essential oil from the leaves of Eugenia stipitata against Ae. aegypti, offering a natural and sustainable alternative for mosquito control. Tests were conducted using third-stage larvae to evaluate larvicidal activity and pupae collected up to 14 h after transformation to investigate pupicidal activity. Throughout the bioassays, the organisms were exposed to various essential oil concentrations. The findings demonstrated that the essential oil of E. stipitata exhibited larvicidal action, resulting in 100% larval mortality after 24 h and an LC50 value of 0.34 mg/mL. The effectiveness of essential oil as a pupicidal agent was also demonstrated by its LC50 value of 2.33 mg/mL and 100% larval mortality in 24 h. It can be concluded that the essential oil of E. stipitata holds promise as a natural pest control agent. Its use may reduce the reliance on conventional chemical pesticides, providing a more sustainable and effective strategy to combat diseases spread by mosquitoes.

The Ethnopharmacology, Phytochemistry and Bioactivities of the Corymbia Genus (Myrtaceae).

Plants have been vital to human survival for aeons, especially for their unique medicinal properties. Trees of the Eucalyptus genus are well known for their medicinal properties; however, little is known of the ethnopharmacology and bioactivities of their close relatives in the Corymbia genus. Given the current lack of widespread knowledge of the Corymbia genus, this review aims to provide the first summary of the ethnopharmacology, phytochemistry and bioactivities of this genus. The Scopus, Web of Science, PubMed and Google Scholar databases were searched to identify research articles on the biological activities, phytochemistry and ethnomedical uses of Corymbia species. Of the 115 Corymbia species known, 14 species were found to have ethnomedical uses for the leaves, kino and/or bark. Analysis of the references obtained for these 14 Corymbia spp. revealed that the essential oils, crude extracts and compounds isolated from these species possess an array of biological activities including anti-bacterial, anti-fungal, anti-protozoal, anti-viral, larvicidal, insecticidal, acaricidal, anti-inflammatory, anti-oxidant, anti-cancer and anti-diabetic activities, highlighting the potential for this under-studied genus to provide lead compounds and treatments for a host of medical conditions.

Essential Oils of Five Syzygium Species Growing Wild in Vietnam: Chemical Compositions and Antimicrobial and Mosquito Larvicidal Potentials.

The essential oils of five Vietnamese Syzygium species (Syzygium levinei, S. acuminatissimum, S. vestitum, S. cumini, and S. buxifolium) were first hydro-distilled and analyzed using GC-FID/MS (gas chromatography-flame ionization detection/mass spectrometry). Monoterpene hydrocarbons, sesquiterpene hydrocarbons, and oxygenated sesquiterpenoids were the main chemical classes in these oils. All these essential oils showed good-excellent antimicrobial activities against Gram-positive bacteria Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus, and the yeast Candida albicans. S. levinei leaf essential oil, rich in bicyclogermacrene (25.3%), (E)-ß-elemene (12.2%), (E)-caryophyllene (8.2%), and ß-selinene (7.4%), as well as S. acuminatissimum fruit essential oil containing (E)-caryophyllene (14.2%), α-pinene (12.1%), caryophyllene oxide (10.9%), ß-selinene (10.8%), α-selinene (8.0%), and α-humulene (5.7%), established the same MIC value of 8 µg/mL against E. faecalis and B. cereus, which were much better than the positive control streptomycin (MIC 128-256 µg/mL). The studied essential oils showed the potential to defend against mosquitoes since they caused the 24 and 48 h LC50 values of less than 50 µg/mL against the growth of Culex quinquefasciatus and Aedes aegypti larvae. Especially, S. buxifolium leaf essential oil strongly inhibited Ae. aegypti larvae with 24 and 48 h LC50 values of 6.73 and 6.73 µg/mL, respectively, and 24 and 48 h LC90 values of 13.37 and 10.83 µg/mL, respectively. These findings imply that Vietnamese Syzygium essential oils might have potential for use as supplemental antibacterial agents or as "green" alternatives for the control of mosquitoes.

Potential anti-inflammatory biomarkers from Myrtaceae essential oils revealed by untargeted metabolomics.

Many species from Myrtaceae have traditionally been used in traditional medicine as anti-inflammatory, antimicrobial, antidiarrheal, antioxidant and antirheumatic, besides in blood cholesterol reduction. In the present work, the anti-inflammatory activity of essential oils from eighteen Myrtaceae spp. were evaluated according to their ex-vivo anti-inflammatory activity in human blood, and the corresponding biomarkers were determined using untargeted metabolomics data and multivariate data analysis. From these studied species, six displayed anti-inflammatory activity with percentage rates of inhibition of PGE2 release above 70%. Caryophyllene oxide (1), humulene epoxide II (2), ß-selinene (3), α-amorphene (4), α-selinene (5), germacrene A (6), ß-bisabolene (7), α-muurolene (8), α-humulene (9), ß-gurjunene (10), myrcene (11), ß-elemene (12), α-cadinol (13), α-copaene (14), E-nerolidol (15) and ledol (16) were annotated as potential anti-inflammatory biomarkers. The results obtained in this study point to essential oils from species of the Myrtaceae family as a rich source of anti-inflammatory agents.

Review of Phytochemicals Present in Psidium guajava Plant and Its Mechanism of Action on Medicinal Activities.

For centuries, herbal remedies have been employed to address a variety of human ailments, and Psidium guajava Linn (Myrtaceae), commonly known as guava, stands out as a noteworthy medicinal plant with significant pharmacological potential. In India, particularly in rural areas where access to conventional medicines can be limited, the various parts of the Psidium guajava plant, including its leaves, bark, roots, and fruit, have been harnessed for their therapeutic properties to tackle various health issues. Psidium guajava Linn proves to be a valuable repository of essential nutrients along with bioactive compounds such as α-terpineol, ß-caryophyllene (trans-caryophyllene), rutin, α-humulene, oleanolic acid, flavonoids, and quercetin. These components exhibit diverse medicinal activities, encompassing anti-inflammatory, anti-cancer, anti-bronchitis, anti-proliferative, anti-tumor, anti-bacterial, and anti-diabetic effects. Every facet of the guava plant holds economic significance and is cultivated on a large scale. Taxonomically, Psidium guajava can be classified within the Plantae kingdom, Magnoliophyta division, Magnoliopsida class, Rosidae subclass, Myrtales order, Myrtaceae family, Myrtoideae subfamily, Myrteae tribe, Psidium genus, Guajava species. This adaptability of guava to various soils and environmental conditions facilitates relatively easy cultivation, yielding rapid fruit production. Its widespread cultivation across India is attributed to its manifold commercial applications. To comprehensively comprehend how this plant can effectively address the array of health challenges encountered by the Indian populace, this review delves into its multifaceted therapeutic properties, highlighting its significance in healthcare practices. Ongoing research endeavors by investigators continue to uncover novel medicinal attributes associated with Psidium guajava, enriching our understanding of its potential benefits.

Neither lysigenous nor just oil: Demystifying myrtaceous secretory cavities.

PREMISE: Leaf subepidermal secretory cavities are a notable trait in Myrtaceae, but their formation is still controversial because of the lack of consensus on their ontogeny among authors. Knowledge about the compounds present in these cavities has grown over the last few years, demonstrating that terpenoid-rich oils are not their unique content. These two points are the focus of this study on the ontogeny, structure, and contents of secretory cavities in neotropical Myrtaceae. METHODS: We used histochemical tests and Raman analysis to verify the basic chemical composition of the cavity contents of nine species. We studied the ontogeny of glands in one species, comparing aldehyde-fixed tissues and fresh sections mounted in an inert medium. RESULTS: We observed schizogenous development and appearance of the secretory cavities and found that sample processing may induce cell breakdown, which can be misinterpreted as lysigeny. The content of these cavities contains putative terpenes, resins, carbonyl groups, and flavonoids. CONCLUSIONS: Our findings support the hypothesis that the lysigenous appearance of the oil glands is a technical artifact. These tissue distortions must be considered when interpreting the development of this type of secretory structure. Moreover, the basic analyses of chemical constituents show for the first time that the glands of neotropical Myrtaceae are potential reservoirs of some compounds such as flavonoids previously reported as novelties for a few other myrtaceous species. Because some of them are non-lipid compounds, the idea that the glands are just oil repositories is no longer applicable.

Phytochemical profiling and neuroprotective activity of Callistemon subulatus leaves against cyclophosphamide-induced chemobrain.

Cyclophosphamide (CPA) is a chemotherapeutic drug used for various types of cancers. However, patients receiving CPA for long periods suffer cognitive impairment associated with difficulties in learning, decreased concentration, and impaired memory. Chemotherapy-induced cognitive impairment, known as chemobrain, has been attributed to enhanced oxidative stress and inflammatory response. The current study aimed to identify the phytoconstituents of Callistemon subulatus extract (CSE) using HPLC-ESI/MS-MS analysis and evaluate its neuroprotective activity against CPA-induced chemobrain in rats. Fourteen compounds were identified following HPLC analysis including, five phlorglucinols, four flavonol glycosides, a triterpene, and a phenolic acid. Forty rats were divided into five groups treated for ten days as follows; group I (control group), group II received CPA (200 mg/kg, i.p.) on the 7th day, groups III and IV received CSE (200 and 400 mg/kg respectively, orally) for ten days and CPA (200 mg/kg, i.p.) on the 7th day, and group V received only CSE (400 mg/kg, orally) for ten days. The administration of CSE effectively ameliorated the deleterious effects of CPA on spatial and short-term memories, as evidenced by behavioral tests, Y-maze and passive avoidance. Such findings were further confirmed by histological examination. In addition, CSE counteracted the effect of CPA on hippocampal acetylcholinesterase (AChE) activity enhancing the level of acetylcholine. Owing to the CSE antioxidant properties, it hindered the CPA-induced redox imbalance, which is represented by decreased catalase and reduced glutathione levels, as well as enhanced lipid peroxidation. Therefore, CSE may be a promising natural candidate for protection against CPA-induced chemobrain in cancer patients.

Chromosome-scale assemblies of S. malaccense, S. aqueum, S. jambos, and S. syzygioides provide insights into the evolution of Syzygium genomes.

Syzygium is a large and diverse tree genus in the Myrtaceae family. Genome assemblies for clove (Syzygium aromaticum, 370 Mb) and sea apple (Syzygium grande, 405 Mb) provided the first insights into the genomic features and evolution of the Syzygium genus. Here, we present additional de novo chromosome-scale genome assemblies for Syzygium malaccense, Syzygium aqueum, Syzygium jambos, and Syzygium syzygioides. Genome profiling analyses show that S. malaccense, like S. aromaticum and S. grande, is diploid (2n = 2x = 22), while the S. aqueum, S. jambos, and S. syzygioides specimens are autotetraploid (2n = 4x = 44). The genome assemblies of S. malaccense (430 Mb), S. aqueum (392 Mb), S. jambos (426 Mb), and S. syzygioides (431 Mb) are highly complete (BUSCO scores of 98%). Comparative genomics analyses showed conserved organization of the 11 chromosomes with S. aromaticum and S. grande, and revealed species-specific evolutionary dynamics of the long terminal repeat retrotransposon elements belonging to the Gypsy and Copia lineages. This set of Syzygium genomes is a valuable resource for future structural and functional comparative genomic studies on Myrtaceae species.

Genus Pimenta: An Updated Comprehensive Review on Botany, Distribution, Ethnopharmacology, Phytochemistry and Biological Approaches.

Pimenta is a genus of flowering plants belonging to family Myrtaceae, native to the West Indies, Mexico, and South America. Numerous traditional uses were reported as anti-inflammatory, analgesic, antipyretic, sedative, diuretic, and sexual stimulant. This article aims to provide a comprehensive overview of the botany, traditional uses, phytochemical profile, and biological activities of genus Pimenta for future exploration of plant-based drugs and therapeutic approaches. The data were collected (up to date as of October 1, 2023) from several databases such as Web of Science, google scholar, science direct, Pubmed and Proquest. Pimenta species were reported to include various classes of phytochemicals like tannins, saponins, flavonoids, phenylpropanoids, monoterpenes, sesquiterpenes and essential oils. Quercetin glycosides and eugenol derivatives were the predominant compounds of this genus. Several biological activities have been reported such as antihypertensive, antioxidant, antimicrobial, antiviral, histidine decarboxylase inhibition, hypoglycemic, anticancer, anti-inflammatory, analgesic, antipyretic, acaricidal, anxiolytic, anti-depressant and anti-estrogenic. Several scientific reports have been published on various isolated phytochemicals and pharmacological properties of Pimenta species that confirm its ethnobotanical and traditional history. However, in vivo studies on different extracts and their phytoconstituents, alongside mechanistic analysis deserve more attention for drug researchers to provide better guidance to utilize Pimenta plants as medicinal resources for herbal formulations in different approaches.

A terpene synthase supergene locus determines chemotype in Melaleuca alternifolia (tea tree).

Leaf oil terpenes vary categorically in many plant populations, leading to discrete phenotypes of adaptive and economic significance, but for most species, a genetic explanation for the concerted fluctuation in terpene chemistry remains unresolved. To uncover the genetic architecture underlying multi-component terpene chemotypes in Melaleuca alternifolia (tea tree), a genome-wide association study was undertaken for 148 individuals representing all six recognised chemotypes. A number of single nucleotide polymorphisms in a genomic region of c. 400 kb explained large proportions of the variation in key monoterpenes of tea tree oil. The region contained a cluster of 10 monoterpene synthase genes, including four genes predicted to encode synthases for 1,8-cineole, terpinolene, and the terpinen-4-ol precursor, sabinene hydrate. Chemotype-dependent null alleles at some sites suggested structural variants within this gene cluster, providing a possible basis for linkage disequilibrium in this region. Genotyping in a separate domesticated population revealed that all alleles surrounding this gene cluster were fixed after artificial selection for a single chemotype. These observations indicate that a supergene accounts for chemotypes in M. alternifolia. A genetic model with three haplotypes, encompassing the four characterised monoterpene synthase genes, explained the six terpene chemotypes, and was consistent with available biparental cross-segregation data.

Acaricidal activity of a 2-methoxy-clovan-9-ol rich fraction from Eugenia copacabanensis (Myrtaceae) extract on Rhipicephalus microplus (Acari: Ixodidae).

Rhipicephalus microplus (Ixodidae, canestrini, 1888) is an invasive ectoparasite of cattle which causes high economic losses in emerging countries such as Brazil. Phytochemical compounds have been tested as an alternative to synthetic acaricides due to potentially lower mammalian toxicity. This study evaluated the acaricidal activity against R. microplus of the 2-methoxy-clovan-9-ol rich fraction obtained from Eugenia copacabanensis Kiaersk.leaves, a little known Myrtaceae species from the Brazilian Atlantic Forest. This fraction was obtained by maceration with methanol, partition with n-hexane and purification by normal-phase column chromatography. GC-MS, 1H and 13C NMR and IR analysis contributed to the identification of a major compound as the sesquiterpene 2-methoxy-clovan-9-ol, reported for the first time for the Myrtaceae family. The fraction was tested against R. microplus unfed larvae and engorged females and a 93% larval mortality was observed at the concentration of 50 mg mL-1. Lower concentrations of the solution tested demonstrated a significant difference in egg mass weight, hatching and control percentage. Experiments with 50.0 mg mL-1 showed significative results, with lower concentration and maximum efficacy for both assays. The IC50 values for unfed larvae and engorged females were 21.76 and 11.13 mg mL-1, respectively. These results were similar to those obtained in other studies with isolated botanical compounds and essential oils. The lower IC50 for engorged females than for unfed R. microplus larvae had also been described for other plant materials, including plants from the same Myrtaceae family. The present result suggested different mechanisms of action of the compound on the reproductive biology of engorged females, improving its effect against egg viability. These results are important for tick control, suggesting that 2-methoxy-clovan-9-ol could be a potential natural acaricidal product against both R. microplus unfed larvae and engorged females.

Extraction Methods, Chemical Characterization, and In Vitro Biological Activities of Plinia cauliflora (Mart.) Kausel Peels.

Plinia cauliflora (Mart.) Kausel, popularly known as jabuticaba, possesses bioactive compounds such as flavonoids, tannins, and phenolic acids, known for their antioxidant, antibacterial, wound healing, and cardioprotective effects. Therefore, this study aimed to standardize the P. cauliflora fruit peel extraction method, maximize phenolic constituents, and evaluate their antioxidative and antimicrobial effects. Various extraction methods, including vortex extraction with and without precipitation at 25, 40, and 80 °C, and infusion extraction with and without precipitation, were performed using a completely randomized design. Extraction without precipitation (E - P) showed the highest yield (57.9%). However, the precipitated extraction (E + P) method displayed a yield of 45.9%, higher levels of phenolic derivatives, and enhanced antioxidant capacity. Major compounds, such as D-psicose, D-glucose, and citric acid, were identified through gas chromatography-mass spectrometry (GC-MS) analysis. Ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis identified citric acid, hexose, flavonoids, tannins, and quercetin as the major compounds in the extracts. Furthermore, the extracts exhibited inhibitory effects against Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli bacteria. In conclusion, the E + P method efficiently obtained extracts with high content of bioactive compounds showing antioxidant and antimicrobial capacities with potential application as a dietary supplement.

Undescribed Phenolic Glycosides from Syzygium attopeuense and Their Inhibition of Nitric Oxide Production.

Four undescribed phenolic glycosides including three stilbene derivatives (1 and 3) and sodium salt of 3 (2), and a chalcone glycoside (4), together with thirteen known compounds (5-17) were isolated from the leaves of Syzygium attopeuense (Gagnep.) Merr. & L.M.Perry. Their chemical structures were elucidated to be (Z)-gaylussacin (1), 6''-O-galloylgaylussacin sodium salt (2), 6''-O-galloylgaylussacin (3), 4'-O-[ß-D-glucopyranosyl-(1→6)-glucopyranosyl]oxy-2'-hydroxy-6'-methoxydihydrochalcone (4), gaylussacin (5), pinosilvin 3-O-ß-D-glucopyranoside (6), myricetin-3-O-(2''-O-galloyl)-α-L-rhamnopyranoside (7), myricetin-3-O-(3''-O-galloyl)-α-L-rhamnopyranoside (8), myricetin-3-O-α-L-rhamnopyranoside (9), quercitrin (10), myricetin-3-O-ß-D-glucopyranoside (11), myricetin-3-O-ß-D-galactopyranoside (12), quercetin 3-O-α-L-arabinopyranoside (13), myricetin-3-O-2''-O-galloyl)-α-L-arabinopyranoside (14), (+)-gallocatechin (15), (-)-epigallocatechin (16), and 3,3',4'-trimethoxyellagic acid 4-O-ß-D-glucopyranoside (17) by the analysis of HR-ESI-MS, 1D and 2D NMR spectra in comparison with the previously reported data. Compounds 1-3, 5, and 6 significant inhibition of NO production in LPS-activated RAW264.7 cells, with IC50 values ranging from 18.37±1.38 to 35.12±2.53 µM, compared to a positive control (dexamethasone) with an IC50 value of 15.37±1.42 µM.